Boating appears to be surging in popularity in California, and nationwide. California agencies combatting the spread of invasive quagga and zebra mussels ask new and seasoned boaters to remain cautious to prevent the spread of quagga and zebra mussels by cleaning, draining and drying their watercraft after each outing.

Quagga and zebra mussels are invasive freshwater mussels native to Europe and Asia. They multiply quickly, encrust watercraft and infrastructure, alter water quality and the aquatic food web, and ultimately impact native and sport fish communities. These mussels spread from one waterbody to another by attaching to watercraft, equipment and nearly anything that has been in an infested waterbody.

Invisible to the naked eye, microscopic juveniles are spread from infested waterbodies by water that is entrapped in boat engines, ballasts, bilges, live-wells and buckets.

A multi-agency effort that includes CDFW, DBW, CDFA and the Department of Water Resources has been leading an outreach campaign to alert the public to the quagga and zebra mussel threats. CDFW’s invasive species e-mail, invasives@wildlife.ca.gov, is available for those seeking information on quagga or zebra mussels.

To prevent the spread of these mussels and other aquatic invasive species, people launching vessels at any waterbody are subject to watercraft inspections and should clean, drain and dry their motorized and non-motorized boats, including personal watercraft, and any equipment that contacts the water before and after use.

CDFW advises boaters to take several steps before leaving a waterbody to prevent spreading invasive mussels, improve the efficiency of your inspection experience next time you launch, and safeguard California waterways. Boaters are asked to: Clean — inspect exposed surfaces and remove all plants and organisms; drain — all water, including water contained in lower outboard units, live-wells and bait buckets; dry — allow the watercraft to thoroughly dry between launches. Watercraft should be kept dry for at least five days in warm weather and up to 30 days in cool weather.

CDFW has developed a brief video demonstrating the ease of implementing the clean, drain and dry prevention method as well as a list of Watercraft inspection Programs statewide. In addition, California State Parks Division of Boating and Waterways (DBW) has a detailed guide to cleaning vessels of invasive mussels and other information available on their web page.